class TTY::Prompt::EnumPaginator

Public Instance Methods

paginate(list, active, per_page = nil, &block) click to toggle source

Paginate list of choices based on current active choice. Move entire pages.

@api public

# File lib/tty/prompt/enum_paginator.rb, line 12
def paginate(list, active, per_page = nil, &block)
  default_size = (list.size <= DEFAULT_PAGE_SIZE ? list.size : DEFAULT_PAGE_SIZE)
  @per_page = @per_page || per_page || default_size

  # Don't paginate short lists
  if list.size <= @per_page
    @lower_index = 0
    @upper_index = list.size - 1
    if block
      return list.each_with_index(&block)
    else
      return list.each_with_index.to_enum
    end
  end

  unless active.nil? # User may input index out of range
    @last_index = active
  end
  page  = (@last_index / @per_page.to_f).ceil
  pages = (list.size / @per_page.to_f).ceil
  if page == 0
    @lower_index = 0
    @upper_index = @lower_index + @per_page - 1
  elsif page > 0 && page <= pages
    @lower_index = (page - 1) * @per_page
    @upper_index = @lower_index + @per_page - 1
  else
    @upper_index = list.size - 1
    @lower_index = @upper_index - @per_page + 1
  end

  sliced_list = list[@lower_index..@upper_index]
  indices = (@lower_index..@upper_index)

  if block
    sliced_list.each_with_index do |item, index|
      block[item, @lower_index + index]
    end
  else
    sliced_list.zip(indices).to_enum unless block_given?
  end
end